Hi, John Youn <John.Youn@xxxxxxxxxxxx> writes: > [ text/plain ] > On 3/18/2016 12:17 PM, John Youn wrote: >> On 3/16/2016 6:56 AM, Felipe Balbi wrote: >>> >>> heh, +john >>> >>> Felipe Balbi <balbi@xxxxxxxxxx> writes: >>>> [ text/plain ] >>>> >>>> Hi, >>>> >>>> Roger Quadros <rogerq@xxxxxx> writes: >>>>> [ text/plain ] >>>>> We will need this function for a workaround. >>>>> The function issues a softreset only to the device >>>>> controller and performs minimal re-initialization >>>>> so that the device controller can be usable. >>>>> >>>>> As some code is similar to dwc3_core_init() take out >>>>> common code into dwc3_get_gctl_quirks(). >>>>> >>>>> We add a new member (prtcap_mode) to struct dwc3 to >>>>> keep track of the current mode in the PRTCAPDIR register. >>>>> >>>>> Signed-off-by: Roger Quadros <rogerq@xxxxxx> >>>> >>>> I must say, I don't like this at all :-p There's ONE known silicon which >>>> needs this because of a poor silicon integration which took an IP with a >>>> known erratum where it can't be made to work on lower speeds and STILL >>>> was integrated without a superspeed PHY. >>>> >>>> There's a reason why I never tried to push this upstream myself ;-) >>>> >>>> I'm really thinking we might be better off adding a quirk flag to skip >>>> the metastability workaround and allow this ONE silicon to set the >>>> controller to lower speed. >>>> >>>> John, can you check with your colleagues if we would ever fall into >>>> STAR#9000525659 if we set maximum speed to high speed during driver >>>> probe and never touch it again ? I would assume we don't really fall >>>> into the metastability workaround, right ? We're not doing any sort of >>>> PM for dwc3... >>>> > > Hi Felipe, > > Do you mean to keep DCFG.speed to SS and set dwc->maximum_speed to HS? > I don't see an issue with that as long as we always ignore > dwc->maximum_speed when programming DCFG.speed for all affected > versions of the core. As long as the DCFG.speed = SS, you should not > hit the STAR. I actually mean changing DCFG.speed during driver probe and never touching it again. Would that still cause problems ? -- balbi
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